The present disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides casing or work string orientation indicating apparatus and methods.
In order to allow accurate azimuthal orientation of a structure (such as a pre-milled casing window, orienting latch profile, production assembly, etc.) in a wellbore, prior orienting systems have typically relied on use of MWD tools or other pressure pulsing orientation indicating devices. Unfortunately, at increased depths, such pressure pulses are increasingly attenuated when the return flow path is restricted (such as, in an annulus between an inner work string and an outer casing or liner string), and pressure “noise” is introduced due to varied restrictions to flow in the return flow path. These conditions make pressure pulses and data transmitted by pressure pulses difficult to detect and interpret at the surface.
Furthermore, typical MWD tools cannot be cemented through, are too valuable to be drilled through, and do not provide for passage of plugs therethrough for releasing running tools, setting hangers and packers, etc. If an MWD tool must be separately conveyed and retrieved from a well, additional time and expense are required for these operations. In addition, conveyance of MWD tools into very deviated or horizontal wellbores by wireline or pumping the tools down presents additional technical difficulties.
Therefore, it may be seen that improvements are needed in the art of indicating orientation of structures in a wellbore.